Helical gear pump with nonrigid casing



Oct. 7, 1952 F, Q BYRAM ETAL 2,612,845

HELICAL GEAR PUMP WITH NONRIGID cAsING Filed April 29, 195o 2 SHEETS-SHEET ll IN VEN TORS. fkfaER/CK C, Bye/:M "7" 650,96 ZMMEQJA.

mu @i ATTORNEYS.

Oct. 7, 1952 F. c. BYRAM ETAI HELICAL GEAR PUMP WITH NONRIGID QAsING 2 SHEETS--SHEET 2 Filed April 29, 1950 ATTORNEYS.

Patented Oct. 7, 1952 HELIGAL'GEARLPUMP WITH NONRIGID CASING llircderickl Cameron Byram; New Carlisle; and

GeorgeH; Zimmer, Jr.,

Springfield; Ohio, aS.'-V

signors to Robbins-dvMyers; Inc., Springfieldjv Ohio, a vcorporation of Ohio'.y

ApplicatonAprilZS, 1950, Serial No. 159,079

13 Claims;l (Cl. 41034-1171) This Yinvention relates to'a .helical gear'pump having anon-rigid casing., The partcularpump to which the invention is appliedis a pump of the type disclosed lby R. J. L. Moineau in his Patentl No. 1,892,217 of VDecember 27, 1932. This pumpis of the type having a stator member with internalhelical grooves or threads and'arotor member with'external helical grooves or threads, the stator member having one threadmore than the rotor member. It is one of the characteristics of a'pump of this type that if the rotor is rotated on itstrue center the stator member orbits 'or wobbles7 about the rotor kmember vin va cylindrical path.

Itis an object'ofthe present invention to provide a pump of the type'outlined above for direct connection to an electriomotorl which-pump will be very much'cheaper than any'pump 4of this type known'heretofore.- Itv isanother object of the present 'invention-'to provide integrally with the :stator member of the pump a member which serves as a portion of the pump casing and intake ordischarge whereby an actual pump casingin the'conventi'onal sense is eliminated', thereby eX- hibiting; asubstantial decrease in manufacturing costs..

Other'obj'ects of the invention include" the provision'v of 'apump as outlined'whioh in addition' to its lower cost will'be lighter and lsmallerthan` other pumps of this nature heretofore known.

These and other objects of. 'our invention which will be :apparent to those 1 skilled in. the art'uponreading .these specifications or which we 'shall describe in greater detail. hereinafter we y accom-- plish by that certain constructionmand arrangement of parts of which Vwe shall now describe certain exemplary embodiments.

Reference is made tothe drawings Vforming a p'art'hereof and in which:

Figure 1 is a plan view of one .embodiment of a pump and motor according to the invention.

Figure 2v is `across sectional view taken on the line 2--2-of Figure 1.

Figure 3f`is an exploded' -View of la portion'of thelmotor casing 'and a portion of' the pump showing the manner of attachment.

Figures and-.5 are fragmentary cross sectional views showing modifications in the manner of attachment.

Figure' `6 Iis- 1a cross-sectional View of another embodiment.

Briey, in.the..practicef=of ourinvention we mold the pump stator `together with an inlet vor outlet extension, if required, and the-major por#l tion of the pump casing'in onepiece from'are^`A silient material suchzasrubber :orA the like:U The` 2. open end ."Qf the pump casing portion vwhich surroundsthestato'r .portionis closed by a shallow panelke head. which is providedfwith' a' shaft entrance` opening'and 'sealing means 'forthe shaft and which' is alsoprovidedwith an'aperture for an inletor` outlet port for 'the pump.' The two pump casingjportions are 'securedv together by an annular joint 'and the pumpas a whole is secured to an annular extension vofthe motor casing so that the pump issecured at only the one annular locus. Because of the `resilience ofthe casing portion of vthe `stator th'ejstator'portion itself is free tofollow the path, ofV movement- 'enforced upon it anda casinginj the usual sense lof the wordy is rendered -unnecessary: Such a casing may, however, be provided'as shown in'Figure 6,' if' it, is'desir'ed to conceal-'the 'wobblingfofthe stator.

In thedrawings, referring-now' particularh'ri to Figures yle'to 3 inclusive, themotor is generally referred to atl0,' and the" pump is generally-re-- ferred to'at II.' The motorlll is 'preferablyprovided with an annular frame-extension indicated at f I 2 to which the lpump 'is annularly secured.'

The stator element of the pump-is indicated at' I3 and, as willlbe-clear from' .an examination ofl 'Fig-urer 2, it is provided vwith 'aport extension at I4 Whichr' is substantially coaxial with the statorportionr I 3 and it is also provided lwithaconic'a'l casing portion' I5' which surroundsth'e stator portion I 3. and extends 'slightly' beyond the end of the stator portion I3. The :conical casingportion :I 5. is .provided rfwithfan' annular 'flange I E, and .preferably the flange 16 is-provided with an annularfbead I l.l

The open end of f the fconicaly portion-'I5 is :closed by a; shallowpan=lileheadz Iawhich may beof lighti-gauge'sheetimetal Iorthe like vandwhich has anY .aperture to -permitentry of the vmotor shaftl Ilia. Azcollarfmember I9isif preferably welded tothe .headlportion lei-about `the 'shaft aperture andthe-:shaft preferably is.` provided' with a rgroove 20 lin 'which-1a snapfring 2'I` may engage. Between the collar-vlaaandflthe snap ring 2li` therefis :provided 'azsealing arrangement which may be; ofiinore o1'. `less:fconventionaiI design, Aern-` tody'ingt alga-suer, Zaans resilient member 23 heldin'.extendedicondition'by 'aspring 2411 The ange Aof' .the resilientfmernber l"lit#bears against the fsnapring 2 If 'and thespring urges the gasket 22 :against fthe *collar I 9 '.thuseffectively sealing the shaft "entrancey opening 'in the head I 8.

A port 'fitting 'f2'51may-be fbrazed, welded "or oth'-l erwise-suitably tsecur'e'd' yinto a port ope'nlrg'ZB' in thefheadzl' It will 'befclear that the 1l'wof fluid throughgthepump lmayrbeeith'er from right to left or left to right in Figure 2 depending upon the direction of rotation of the motor shaft Illa.

The rotor member 21 is preferably secured to the motor shaft Ina by a threaded stud 28 on the end of the motor shaft engaging in a threaded bore in the rotor 21.

Assembly may be accomplished in a number of ways, as shown in Figures 3, 4 and 5. The head member I 8 may be first secured in place and then the rotor 21 may be assembled to the motor shaft Illa. Thereupon the conical portion I may be secured to the head I8, as shown in Figure 3, by an annular grooved ring 29 (the grooves embracing the bead I1 and the head member I8 having a groove member I8a also to accommodate the bead I1) and the ring having an annu` lar extension with suitable holes for the passage of securing bolts 30.

In Figure 4 there is shown a modification wherein the flange of the head member I8 is extended annularly as shown in broken lines at |811 and the flange is first secured in place by means of screws or the like at 3|. Thereafter the extensions portion IBb is spun over to the position shown in full lines at I8c, thus clamping the flange I6 and bead I1 to the head member I 8.

In Figure 5 there is shown a still further modification where an annular clip member 32 is also secured by means of the screws 33 and thereafter the extension I8d of the head flange is spun over to the position shown at I8e.

In operation, when the motor rotates, thus rotating the pump rotor 21, the pump stator I3 is caused to move in a cylindrical path about the axis of the shaft Illa. The resilience of the conical portion I5 of the stator member permits this movement and thus the pump is secured to the motor only in the region of the annular joint between the conical portion I5 and the head member I8. The port extension I4 may be secured in any desired manner to a hose line or the like and, as pointed out above, may serve either as an entrance or exhaust port. The same is true of the fitting 25. In operation thus the entire portions I5 and I4, as observed from the outside, will appear to vibrate at relative high speeds. The pump however is completely sealed from the exterior and has been found to function very efiiciently. Since the casing in the conventional sense of the word has been eliminated, the pump is very much lighter and cheaper than any heretofore available.

Since the port fitting I4 will wobble in a cylindrical path along with the stator I3 the hose connections to the fitting I4 will be continually moved. Thus it may be desirable for some purposes that the port fitting remain fixed, and to this end we have shown a modification in Figure 6 wherein the port fitting I4 has been removed from the end of the stator member and the stator member together with its funnel-like casing portion I5, as shown in Figure 2, has been enclosed within a dome-like casing to which a fixed port fitting is secured.

Referring therefore to Figure 6 we have shown the stator I3 with its funnel-like casing portion I5 as before, and the funnel-like portion I5 is provided with the annular flange I6 having the bead I1 as described above. Again the open end of the funnel-like casing portion I5 is closed by a relatively shallow pan-like member indicated at 40 having an annular flange 4I terminating peripherallv in a groove 42 for engagement with the bead I1. The member 40 is provided with a port fitting at 43 which may be brazed in place as shown at 44. The member 40 is provided with a central flanged aperture for the passage of the drive shaft from the motor and the annular fiange 45 serves as a support and fastening element for the seal indicated generally at 48. Since the seal forms no part of the present invention it will not be described in detail. The head 40 is suitably secured to a bracket 41 which carries the bearings 48 for the drive shaft 49. The drive shaft 49, as before, may have the threaded end 50 for engagement in the threaded hole 5I of the rotor 21. Thus far in all essential respects the device of Figure 6 is the same as that of Figure 2. It will be observed however that the port fitting I4 has been omitted from the end of the stator I3 and that a member 52 has been provided in the nature of a casing. The member 52 is provided with a peripheral flange 53 which terminates in the annular peripheral groove 54 matching the groove 42 of the head. In assembly the two grooves 54 and 42 embrace the annular bead I1 and these elements are held in assembled relation by means of the clamping ring 55 as shown. The clamping ring 55 may be provided with upstanding ears 56 clamped together by means of nut and bolts indicated generally at 51.

The casing member 52 may be spun or drawn from relatively light gauge sheet metal and may have secured thereto, as by brazing or otherwise, the port fitting 58.

It will be clear that the only significant change from the device of Figure 2 is in the provision of a supplementary casing 52 with a fixed port fitting.

It will be clear that numerous modifications may be made without departing from the spirit of our invention, and we therefore do not intend to limit ourselves in any way whatsoever except as set forth in the claims which follow.

Having now fully described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A stator for a helical gear pump, comprising an internally helically grooved cylindrical member, and a conical casing member, said casing member, at its small end, merging with one end of said cylindrical member, and towards its large end fiaring away from said cylindrical member over substantially the length of said cylindrical member, said stator being of resilient material.

2. A stator according to claim l, having a tubular extension substantially coaxial with said cylindrical member, and extending oppositely to said conical casing member, said extension constituting a port fitting.

3. A stator for a helical gear pump, comprising an internally helically grooved cylindrical member, and a conical casing member, said casing member, at its small end, merging with one end of said cylindrical member, and towards its large end flaring away from said cylindrical member over substantially the length of said cylindrical member, and having at its flaring end an annular beaded fiange, said stator being of resilient material.

4. A stator according to claim 3, having a tubular extension substantially coaxial with said cylindrical member, and extending oppositely to said conical casing member, said extension constituting a port fitting.

5. A helical gear pump comprising a stator member constituted of an internally helically grooved cylindrical member, and a conical casing member, said casing member, at its small end, merging with one end of said cylindrical memring for said pump.

ber, and towards its large end flaring away from said cylindrical member over substantially the length of said cylindrical member, said stator being of resilient material, a pan-like casing element for closing the flaring end of said casing member, said pan-like casing element having a shaft entrance opening and having also a port opening for said pump, a shaft entering said shaft entrance opening, and an externally helically grooved rotor element secured to said shaft within said casing members, said one end of said cylindrical member constituting also a port opening for said pump.

6. A pump according to claim 5, wherein a tubular extension constituting a port fitting is provided on said cylindrical member substantially coaxial therewith, and extending oppositely to said conical casing member, and wherein said pan-like element and conical element together constitute the entire pump casing.

7. A pump according to claim 5, wherein there is provided a covering member secured to said pan-like element and covering and concealing said stator member, said covering member having a port fitting.

8. The pump of claim 5 in combination with an electric motor, said shaft being the shaft of said motor, and said motor having an annular frame extension, and said casing elements being annularly secured to said frame extension.

9. A helical gear pump comprising a stator member constituted of an internally helically grooved cylindrical member, and a conical casing member, said casing member, at its small end,

merging with one end of said cylindrical member, and towards its large end flaring away from said cylindrical member over substantially the length of said cylindrical member, said stator being of resilient material, a pan-like casing element for closing the flaring end of said casing member, said pan-like casing element having a shaft entrance opening and having also a port opening for said pump, a shaft entering said shaft entrance opening, and an externally helically grooved rotor element secured to said shaft within said casing members, said one end of said cylindrical member constituting also a port opensaid conical casing member and pan-like casing element being joined and sealed annularly. and said pump being xed to a 6 support annularly in the region of said annular joint.

10. A pump according to claim 9, wherein a tubular extension constituting a port fitting is provided on said cylindrical member and substantially coaxial therewith, and wherein said pan-like element and conical element together constitute the entire pump casing.

11. A pump according to claim 9, wherein there is provided a covering member secured to said pan-like element and covering and concealing said stator member, said covering member having a port fitting.

12. The pump of claim 9 in combination withA an electric motor, said shaft being the shaft of said motor, and said motor having an annular frame extension, and said pump being secured to said annular frame extension in the region of said annular joint.

13. A helical gear pump comprising an externally helically grooved rotor element, means for rotating said rotor element on its true axis, a stator member comprising an internally helically grooved cylindrical element, and means mounting said stator member to permit the movement thereof in its enforced cylindrical path, said means comprising a casing portion of resilient material, secured adjacent an end thereof to said stator member, said casing portion being secured also to a second casing portion of rigid material, said rigid casing portion having a bearing for said rotor axis, and having a port opening.

FREDERICK CAMERON BYRAM. GEORGE H. ZIMNIER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,233,599 Nuebling July 17, 1917 1,892,217 Moineau Dec. 27, 1932 2,505,136 Moineau Apr. 25, 1950 2,512,764 Byram June 27, 1950 2,512,765 Byram June 27, 1950 FOREIGN PATENTS Number Country Date 622,583 Great Britain May 4, 1949 

